Objectives: Cardiovascular disease remains the most common cause of death in patients with type 2 diabetes mellitus. Because periodontitis is a risk factor of cardiovascular disease, identification of risk factors of periodontitis is valuable to control periodontitis effectively. The purpose of this study was to examine the association of education and household income with periodontal status in patients with type 2 diabetes mellitus.Methods: Participants were 2,436 patients (59.8% male, aged 29-93 years) with type 2 diabetes mellitus from 27 medical clinics. Participants' medical records and information about education, household income, general health status, and health behaviors were collected. Periodontal status was assessed in a nearby dental office. Multiple linear regression analyses and ordered logistic regression analyses were conducted to examine the association of periodontal parameters with education and household income after adjusting for age, sex, general health status, and health behaviors.Results: Multiple linear regression analysis showed that mean probing pocket depth was not significantly associated with education and household income. Ordered logistic regression analyses showed statistically significant odds ratios (ORs) of junior high school (reference: university) for the tertiles of the percentage of sites with bleeding on probing (OR: 1.42; 95% confidence interval [CI]: 1.11-1.81), percentage of mobile